Us four under two birtch trees

Us four under two birtch trees

Monday 21 December 2020

 Wall stablizing lattice

 So after my hand got back in working condition we started to fit the yurt type lattice. I'm not so sure this was necessary, as the movement seemed to be gone from the structure after the straw bales were done. The walls now had 2 additional horizontal members, the tops and bases of the windows and between them the 4X2's which sandwich down the bales.

But to be really sure there would be no horizontal movement when the wind picks up we added a lattice made up of 2X1 inch timbers. These we prebent by stacking them fresh from the saw mill, supporting them at either end and putting big rocks to press them down in the middle. I later found out I should have bent them an extra 15% to allow for bounce back.

Prebending the 2X1's. Thanks Jakob and Pirmin for lifting up these big rocks!

 

The lattice is made up of a double layer of 2X1's (50X25mm) fixed top and bottom with 6x100mm screws. Each cross gets a 5x50mm screw.

When we started the lattice I just pushed each one against the bale by hand and had a helper fix them at the top and bottom ends. After doing one wall like this I realized the wall was bulging in. So for the other walls each pieced was clamped by pushing one or two sash clamps thru the wall and really squeezing the 2x1 into the bale. Each one needed to be over bent to end up with an evenly curving wall.

After bending a piece we would tie it in place using baling twine thru the wall, then fix the next one. This was a very time consuming job, each of the 9 sections took about a week.

If I was to do it again I would try to build the lattice first and build the straw bales up against it. But its nice to feel sure that there should not be any movement from the wind loads.


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